Patent Literature 1 describes a vehicle driving system that includes a left wheel driving system having a first motor configured to drive a left wheel of a wheeled vehicle and a first planetary gear type speed changer provided on a power transmission path between the first motor and the left wheel and a right wheel driving system having a second motor configured to drive a right wheel of the wheeled vehicle and a secondary planetary gear type speed changer provided on a power transmission path between the second motor and the right wheel. In the first and second planetary gear type speed changers, the first and second motors are connected to sun gears respectively, the left wheel and the right wheel are connected to planetary carriers respectively, and ring gears are connected to each other. A brake and a one-way clutch are provided on the ring gears that are connected together. The brake brakes the rotation of the ring gear by releasing or fastening the ring gear. The one-way clutch is engaged when the rotational power of the motors side in one direction is inputted into the wheels side, is disengaged when the rotational power of the motors side in the other direction is inputted into the wheels side. The one-way clutch is disengaged when the rotational power of the wheels side in one direction is inputted into the motors side and is engaged when the rotational power of the wheels side in the other direction is inputted into the motors side.
It is described that in the vehicle driving system, when the rotational power of the motors side in the one direction is inputted into the wheels side, the brake is applied so that the motors and the wheels are put in a connected state and that when the vehicle speed reaches or exceeds a predetermined speed with the motors and the wheels being in the connected state, the brake applied is then released.